'Computing' have had a few pro linux articles recently, it may be worth giving them a try. <insert URL of computing here>. Mostly from sun though IIRC, so it may be a bit partisan. There may be some links to what your're looking for perhaps...
And I'm sure there is a write up of that samba vs. NT test knocking about somewhere, it may give you a few quotes...
Thanks! The course is called "Computer Architecture and Communications", so I'm gonna use kernel.org for the fact that the kernel has been ported to Intel, SPARC, Alpha, etc.
I found the SAMBA article (via samba.org), however, I haven't yet found proper figures yet. I've also found some stuff on the relative benefits of Linux's TCP/IP stacks performance, but again, summaries with no hard data. grrr. :-/
Thanks for the help! (Off to search computing journals in the library)
Ricardo